有机电子注入材料对Cs_2CO_3阴极结构电子注入能力的影响

The dependant of electron injection ability on organic electron transporter for cesium carbonate based cathode structure

系统对比了不同有机传输材料与Cs2CO3组合对阴极电子注入能力的影响。结果表明,二氮菲类衍生物与Cs2CO3组合电子注入能力最好,唑类衍生物次之,但都明显好于目前常用的Alq3材料。通过进一步比较发现,电子注入能力与有机材料的能级结构没有直接关系,这说明阴极界面处Cs2CO3与有机材料会发生不同程度的化学作用,从而改变电子注入势垒。对于金属螯合物而言,Alq3的电子注入能力明显强于Liq,说明配位金属可能参与了该作用过程。研究表明了Cs2CO3对有机材料具有较强的选择性,可以为设计合成针对Cs2CO3阴极结构的有机电子材料提供参考。

The electron inj ection ability of cesium carbonate based cathode structure has been studied by changing the organic electron transporters.It was shown that the organic light emitting devices using phenanthroline de-rivatives perform the largest current characteristics,and that with oxadiazole derivatives show the second large current,both of which exhibit much better electron inj ection capability than that of Alq3 .Further studies indi-cate that the electron inj ection ability was irrelevant with energy distribution of each organic materials,thus a different chemical interaction between cesium carbonate and organic materials can be deduced happening at cath-ode interface,which would differ the electron inj ection barrier.For the metal chelate complex,the metal cation is expected involving this interfacial interaction because in that an abrupt change in electron inj ection has been found when changing organic materials from Alq3 to Liq.Here a strong influence on the electron injection ability for cesium carbonate cathode structure has been demonstrated by differing organic materials,which would give a hint for designing a novel organic electron transporter for this kind of cathode structure.